1. Field of the Invention
The present invention relates to a side air bag device, an occupant protection device and an occupant protection method for protecting a passenger from a shock caused by a side impact on a side wall of a vehicle (hereinafter merely referred to as a side impact) by expanding a side air bag member between a passenger on a vehicle seat and the side wall of the vehicle, and more particularly, to a side air bag device, an occupant protection device, and an occupant protection method capable of suppressing an interference with a head protective air bag member (hereinafter referred to as a curtain air bag member).
2. Description of Related Art
There has conventionally been known a side air bag device that expands a side air bag member between a passenger and a side wall of a vehicle (hereinafter referred to as a side door) so as to cover a door trim of the side door, during a side impact, thereby protecting mainly a shoulder, chest, and waist of the passenger from the side impact.
There has also been known an occupant protection device and an occupant protection method provided with the side air bag device and a curtain air bag device. Specifically, in the occupant protection device and the occupant protection method described above, the curtain air bag device expands a curtain air bag member between the passenger and the side door, during the side impact, so as to cover a window glass of the side door, thereby being capable of mainly protecting a head of the passenger from the side impact.
For increased safety to side impact, in order to not only protect the shoulder or the head of the passenger but also prevent the passenger from being thrown from the vehicle, an occupant protection device and an occupant protection method described below have been demanded. Specifically, it has been demanded that a curtain air bag member is expanded below a door belt of the side door that is the boundary between the window glass and the door trim (i.e., the occupant protection device and occupant protection method capable of dealing with a so-called rollover have been demanded).
The occupant protection device and the occupant protection method have a problem of interference between the side air bag member and the curtain air bag member, since the curtain air bag member is expanded below the door belt.
In other words, the occupant protection device and the occupant protection method have a technical problem that an appropriate expansion and development of each member might be hindered due to the interference between the curtain air bag member and the side air bag member.
In order to prevent the interference between the curtain air bag member and the side air bag member for securing the appropriate expansion and development of each member, it is considered that the size of the side air bag member in the vertical direction of the vehicle is set to be short.
However, if the size of the side air bag member in the vertical direction of the vehicle is set to be short, there is a possibility that the shoulder of the passenger, which is to be protected by the side air bag member, cannot be protected.
In view of this, Japanese Patent Application Laid-Open (JP-A) No. 2007-050847 describes, as a device capable of preventing the interference between the curtain air bag member and the side air bag member, a side impact air bag device in which a shoulder protective bag portion of a side air bag falls down toward a compartment in the widthwise direction of the vehicle, whereby an appropriate expansion of a head protective bag can be secured, when the side air bag and the head protective air bag interfere with each other.
In JP-A No. 2007-050847 described above, the shoulder protective bag portion of the side air bag member is pressed by the curtain air bag member for allowing the side air bag member to fall down toward the compartment in the widthwise direction of the vehicle in order to secure the appropriate expansion and development of the head protective bag (corresponding to the curtain air bag member) as described above.
Specifically, in JP-A No. 2007-050847, the side air bag member does not avoid the curtain air bag member. Therefore, the portion of the side air bag member pressed by the curtain air bag member is not constant. Accordingly, in JP-A No. 2007-050847, the expansion of the side air bag member in the appropriate direction might be inhibited, that is, the shoulder protective bag portion of the side air bag member might be fallen down to the outside in the widthwise direction of the vehicle.
In JP-A No. 2007-050847, a reaction force is generated because the side air bag member is pressed by the curtain air bag member. The side air bag member repels the curtain air bag member by the reaction force, which might inhibit the expansion of the curtain air bag member in the appropriate direction.
In JP-A No. 2007-050847, the side air bag member might be cured since the side air bag member is pressed by the curtain air bag member, resulting in that an injury level of a passenger might be increased.
As described above, the technique described in JP-A No. 2007-050847 has room for improvement for surely securing the appropriate expansion of the side air bag member and the curtain air bag member. Accordingly, the technique described in JP-A No. 2007-050847 has room for improvement for increasing safety to a side impact.